#kw1{
    margin-left: 280px;

}
/*子标签选择器*/
div h3{
    text-align: center;
}

.div1:hover{
            border: 2px solid;
            background: #1d4d95;
            width: 800px;
            height:500px;
            margin: 50px  auto;
            background-image: url("../imgs/slide.jpg")
        }